Clarence ringwald



Feb. 27, 1934. c. RINGWALD Re-'19097 FUSE Original Filed Dec, 225, 19272 Sheets-Sheet 1 C. RINGWALD Feb. 27, 19.34.

FUSE

, 1927 2 Sheets-Sheet 2 Original Filed Dec. 23

Cf 7106772??? Clarence Fing r1/aid v Jiffy@ Reissued Feb. 27, 1934PATENT OFFICE lacs? Fuse Clarence Bingwald,

by mesne assignments,

Springfield, Ohio, assigner,

to Schweitzer & Conrad,

Inc., Chicago, Ill., a corporation o! Delaware Original No. 1,862,317,dated June 7, 1932, Serial No. 242,137, December 23, 1927.

February 21, 1933, Serial No.

18,743, lated Reissue No.

629,945, August 22, 1932. This application for reissue July 14, 1933.Serial No. 680,445

75 Claims. (Cl. 200-120) rkMy invention relates to electric fuses andthe In protective schemes for preventing excessive current ow, it hascome to be generally recognized that the most simple and reliableindication of excessive current flow is the liberation of heat. Thefusible link has become the recognized standard protective device forrelatively low current ilow circuits and is also in large use n forcurrents o! high amperage, regardless of voltage. l

Where the power becomes relatively great, or the current ilow relativelygreat, other protective means are more generally employed. The u chiefreason for this distinction resides in two things: rst, the amount, i.e., the mass of metal which will be blown, i. e., fused and vaporized,and, second, the limiting strength of the circumambient medium, i. e.,air, in the case of the zo usual small unlled fuse.

l Numerous schemes have been devised for increasing the distance betweenterminals when the fuse blows so as to diminish the amount, i. e., massof metal to be blown to give a certain clearance. Also various schemesof providing a surrounding envelope of a medium i higher dielectricstrength than air have been proposed. In some cases both means have beenprovided.

My invention, while it may be embodied in a 3o fuse wherein theterminals are separated to a greater extent upon blowing oi the fusibleelement, is primarily concerned with the provision of a surroundingmedium oi greater strength than air and which has certain inherent beneuficial effects in the extinction of 'an arc and in the application ofthis medium to the container so as to maintain the desired relationbetween this substance and the active fuse element.

Where a mass of metal between two conduct- 40 ing terminals isvaporized, a ilow of conducting.

electrons appears to be maintained. In the case of metal vapors, theconduction appears to occur very much as in the case of solidconductors, i. e., by a flow of electrons through the adjacentmolecules. In the case of the breakdown of air, it

appears that there are two things which conduct the current flow. First,the molecules of gas are broken down to force electrons from theirorbits, and, second, a certain amount of metal vapor is freed from theterminals. In the case of a corona or brush discharge substantially nometal vapor is released and, hence, a relatively high resistance ismaintained in the arc or spark. If the metal vapor can be kept fromforming, or if it could be eliminated, the air would continue to afforda fairly high resistance, even though it were broken down.i

I have conceived the possibility of surrounding the arc with a substancewhich will initially aiford a highresistance to current iow, i. e.,constitute of itself an excellent insulating medium ol very highdielectric strength; and which, in conjunction with the vaporized metalof the electric arc, will tend to react to form a compound of such highresistance as to bind the electrons in unions which will resistdisruption and, hence, resist current flow with consequent stoppage oithe arc. n

Such compounds are generally disintegrated in the electric arc and,hence, if chilling can be occasioned at the same time that the compoundsare formed, or if the energy of the arc can be sufficiently dissipatedto let these compounds cut down the iiow of current, the arc can beextinguished in a simple and efficacious manner.

For example, assume that when a metal vapor is formed I could combinethe metal with oxygen to form a high resistance oxide. II this reactioncould be carried on more rapidly'than metal vapor could be released, itwill be possible at once to snap out an arc positively and eiectively.

So far, I have not found it possible in atmospheric air to providesufficiently rapid oxidation and chilling to secure this result. With asuitable clrcumambient medium it can be done.

One diiliculty with plain oxidation is the tact that the reaction offree oxygen with the usual metals is exothermic, with the result thatundesirable heat is liberated adding to the violence of the explosion.

I have conceived the possibility of liberating or releasing from asuitable compound the reagent which is to unite with the metal by meansof an endothermic reaction. This compound, as above explained, should bea high dielectric afiected only by the heat of the arc and resistant oiitself to current ilow.

The reagent which I have thus far employed successfully is chlorine.Chlorine reacts with metals in vapor form with great rapidity. I see noreason why other halogens should not operate equally well and shallshortly conduct experiments to determine the suitability of the rest ofthe halogen group. I conceive fluorine, which is more active thanchlorine, will perhaps give superior results. Bromine may also be used.

The particular substance which I have thus far successfully employed incarrying out my invention is chlorinated naphthalene, which is now nfound on the market under the trade name of Halowax. It appears on themarket in various grades including a liquid and a solid or wax form.

Now in order to teach those skilled in the art how to practice myinvention, I shall describe in conjunction with the accompanyingdrawings specic embodiments of my invention.

In the drawings:-

Fig. l is a longitudinal section through a simple elementary form of adevice embodying my invention;

Fig. 2 is a similar view of a modification;

Fig. 3 is a longitudinal section of a fuse embodying my invention;

Fig. 4 is an end view of the same with the end cap removed as thoughtaken on the line 4-4 of Fig. 3;

Fig. 5 is an end view of the terminal as though viewed from the left ofFig. 3;

Fig. 6 is a side elevational view of the active fuse element employed inFig. 3;

Fig. 7 is a longitudinal section of a modified embodiment of myinvention;

Fig. 8 is a plan view of the holder for the active element;

Fig. 9 is a longitudinal section view of the active element shown inFig. 7;

Fig. 10 is an end view of one of the caps of the outer shell of the fuseshown in Fig. '7;

Fig. 1l is a longitudinal sectional view of a spring operated fuseembodying my invention;

Fig. 12 is a longitudinal sectional view of an expulsion type of fuseembodying my invention; and

Fig. 13 is a diagram illustrating the fundamental method involved in.the extinguishment of an arc in accordance with my invention.

Referring now to Fig. 1, I show therein a metal fuse element l havingthe enlarged terminals 2-3 and having a link 4 of reduced cross sectionpreferably at the central part of the fuse. The link 4 and the adjacentportions of the fuse are contained within a sleeve 5 which is preferablymade of iiber or paper impregnated with a Waxlike compound whch, uponbeing heated frees chlorine or other halogen for cooperation with themetallic vapor of the fuse.

Within the sleeve or tube 5 there is a filling 6 of the same wax-likematerial.

The substance which I have successfully utilized for this purpose ischlorinated naphthalene, which I am able to secure on the open marketunder the trade name of Halowax. This material looks much like paraffin,having sometimes a slightly yellowish tinge; it has a high dielectricstrength of the order of 250 to 1000 volts per mill in small nlm. Itsmelting point is around 190 to 205 degrees F. Its boiling point is from610 to 650 degrees F. Its resistivity is of the order of 1500 l010 ohmsper inch cube. Its specific gravity is about 1.589. When brought to theboiling, or approximately the boiling point, it has low viscosity andreadily penetrates brous bodies. At all normal temperatures and undernormal conditions it is neutral and noncorrosive in respect to metals.It is soluble in practically all organic solvent liquids and oils whenheated therewith. It is insoluble in caustic alkaline and acid solutionsexcept those that are powerful oxidizers. It is anhydrous andnon-hygroscopic and therefore will not draw or support a film ofmoisture. It is in its crystallization or in its solid form entirelyfree of moisture. It is a. relatively soft solid, crystalline andtranslucent.

The chlorinated naphthalene may be secured in various grades, but theabove form is the preferred form, since the solid form holds its shapeunder all normal atmospheric conditions.

The paper or fibrous sleeve 5 is bodied in the chlorinated naphthaleneto impregnato the same.

In Fig. 2 I have shown the elements of a fuse in which the sleeve 5impregnated with chlorinated naphthalene is used alone, the heat of thearc caused by volatilizing or the fusible link 4 driving some oi' thearc extinguishing substance from the impregnated Walls of the tube 5 tofill the said tube 5 with active vapor. If desired, the ends of the tube5 may be obstructed to assist in this action, or they may be ,completelyclosed upon the body of the fuse.

In the form shown in Fig. 1, the outer sleeve 5 may be made of othermaterial. since the mass 6 of chlorinated napthalene serves to performthe desired function of extinguishing the arc independently of theevolution of any vapor or gas from the sleeve or envelope 5.

In Figs. 3 to 6 I have shown a commercial form of cartridge fuseembodying my invention. In this form the outer protective sleeve 7 ispreferably a bakelite tube or a tube of ber impregnated with bakelite orthe like. The ends of the tube 7 are threaded as indicated at 8 and 9and in each end transverse slots 10-11 are cut across the edge or marginof said sleeve '7.

An end plate member 12 having the disc 13 and the knife blade contact 14is seated upon the end of the sleeve 'i at each end. A flanged ring 15having the inturned margin 16 embraces the edges of the disc member 13and is threaded down onto the threads 8, as shown in Fig. 3. The discmember i3 has two key members 17 and 18 adaptedto enter the slots l0 and1l so as to anchor the knife blade member 14 rigidly in predeterminedalignment. The construction of the sleeve '7 and of the terminal memberscooperating therewith is identical at each end. The active elementwithin the cuter shell comprises a sleeve 20 preferably made of paper orfiber impregnated with chlorinated naphthalene of the character abovedescribed. A pair of discs 2i and 22 cover the ends of the sleeve 20 andthese discs are slotted to receive the fusible element 1 having thereduced cross section link 4. The ends of the fuse 1 extend through thediscs 21 and 22 and are clinched or bent over as shown in Fig. 4. Forthe purpose of equalizing the bearlng of the disc member 13 against saidclinched end, the end of the fusible element 1 is preferably split andthe two ends are bent over in opposite directions as indicated at 23 and24 in Fig. 4. It can now be seen that the renewable element shown inFig. 6 may be inserted inside the outer sleeve 7, the flanged ring 15and the terminal element 12 being removed. The clinched ends 23-24 bearagainst the disc or plate portion 13 of the terminal element 12 at eachend, and when the ring 15 is screwed down contact is thereby madebetween said ends of the fuse and the knife blade temilnals 14-l4.

In Figs. to 10 I have illustrated a cartridge form of fuse withrenewable element more particularly adapted for larger capacities. Inthis form I provide an outer casing 25 from which the knife bladeterminals 26-26 project. The outer casing 25 comprises a sleeve 27preferably made cf bakelite or bakelized liber having its ends threadedto receive the caps Z13- 28, these caps being threaded to cooperate withthe ends of the tube 2'7. The caps 28-28 contain central slotted discmembers 29-29 having a slot 30' therethrough for receiving the knifeblade terminals 2626. These slotted discs 29 are rotatable in the capmembers 28-28. The cap members 28 may be of metal or they may be ofbakelite or bakelized ber or the like.

While both discs 29-29 are herein shown as rotatable, obviously one ofthem may be anchored and be non-rotatable with respect to its cap 28 ifso desired.` Also it will be apparent that if desired the caps 28 may beformed into the shape ot flanged rings only, as shown in Fig. 3, and thediscs 29-29 extended out to rest upon the ends of the sleeve 27 is sodesired. The knife blade terminals 26-26 extend inwardly towards eachother at their inner ends and these inner ends are shaped to formsemi-cylindrical sockets to receive a cradle member 30 which ispreferably a semi-cylindrical sleeve of hard fiber or the like. Thissleeve of hard iiber 30 is secured to the semicylindrical ends 31-31 ofthe knife blade terminals 26-26 by tubular rivets or the like, asindicated at 32-32.

Preferably the knife blade terminals 26-26 and the semi-cylindricalsocket members 31 are formed integrallyof a stamping of copper or brass.The shank of the knife bla'de contacts 26 adjacent the sockets 31--31 isenlarged to form shoulders 33--33 for limiting the endwise motion of thecradle in the outer casing 25. l

These shank members are also provided with threaded openings 34-34 forreceiving clamping screws 35, the said clamping screws being adapted topass through holes 36-36 in the ends of the active element shown in Fig.9. The renewable element comprises the fuse l preferably having link ofreduced cross-section 4 enclosed in an outer shell or casing 37 havingend caps 38-38.

The end caps and the shell 37 may be made of paper or fiber impregnatedwith chlorinated naphthalene, and the said fuse element 1 supported insaid end caps, which are in turn connected together to the end sleeve37. Ii' desired a lling 38' of the solid wax-like chlorinatednaphthalene may be employed within the sleeve 37.

For the renewal of the active fuse element. the renewable member isreleased at the screws 35-35 and a new element dropped into the cradleshown in Fig. 8, whereupon the ends of the fuse 1 are clamped by thescrews 35. then one end or knife blade terminal 26 is passed through aslot in the disc 29. then the cap at the opposite end with its disc 29is passed over the adjacent knife blade contact 26 and the cap member 28is screwed up tight on the outer sleeve 27.

In Fig. 11 I have shown a fuse in which the fuse terminals are separatedby means of a spring when the fuse element melts. In this case I providean outer container formed of a piece of glass tubing 41 which has a cap42 preferably of brass cemented upon the lower end of the same orotherwise suitably secured thereto, and a sleeve or ferrule 43 cementedor otherwise secured to the upper end thereof. The sleeve 43 extendsbeyond the end of the glass sleeve 41 to provide a seat for thedisc-like cap member 44 which preferably has a flange 45 turned uparound the rim of the same to provide a wider sealing surface. Thecentral part of the cap 46 is preferably bowed up, and under the tensionof the spring 47, which acts upon it, this central arched portion 46 ispulled downwardly, tending to spread the edges oT-the disc into thelside engagement with the counterbore of the ferrule 43.

The fuse element comprises a link 48 preferably having a smallcross-section at the point where the blowing is to occur, and connectedto suitable metallic terminals 49 and 50. These terminals and the fuseelement are imbedded in a mass or filing 51 of chlorinated naphthalenein wax form, said filling being contained within a sleeve 52 formed ofber or paper impregnated with the same substance. The terminal 50 isconnected to the sleeve 52 by a transverse pin 53 extending through bothof said elements. The spring 47 is secured to the lower end of theterminal member 50 and to an anchor 54 formed on the cap member 42. Thespring 47 is placed in tension and the upper terminal member 49 ispassed through an opening in the cap member 46 and is thereanchored asby soldering or by forming a button or the like upon the end of theterminal 49 which is then drawn down tight into engagement with theedges of the hole formed in the cap member 44.

It is not essential that the casing be absolutely fluid tight, but it isdesirable that it be so to the extent of excluding moisture.

Upon blowing of the fusible portion 48, the arc extinguishing material,i. e., the chlorinated naphthalene, is immediately available to attackthe substance of the arc and form with it nonconducting compounds,which, being chilled by the presence of the mass of material and thesleeve outside of the same, becomes a non-conductor of electricity. Atthe same time, the terminals are separated to increase the length of theare and. hence, its vulnerability to attack.

The sleeve 52 with its filling 51 of chlorinated naphthalene is drawndown with the spring 47 so that the movable terminal 50 is surrounded bya bath or mass of the chlorinated naphthalene regardless of the positionof the fuse.

Obviously, the upper end of the sleeve 52 might be attached to the capmember 44, and the terminal 50 pulled down through the mass of arcextinguishing material, but this would expose the glass sleeve 41 to theheat of the arc directly, and that is not desirable.

To avoid exposing the upper end of the glass sleeve to the heat of thearc, I provide a sleeve or lining 56 of paper or fiber impregnated withchlorinated naphthalene at the upper end of the glass sleeve Where theglass might be exposed to the arc by a downward movement of the movablesleeve 52. If the arc persists until one of the terminals 49 or 50 iswithdrawn from the tubular member 52, the arc then occupies the largerbore in the tubular member 56 and the arc extinguishing material carriedby the member 56 is acted upon by the arc to evolve gaseous areextinguishing medium therefrom which tends to fill the space occupied bythe arc. If the cap 44 has been blown oil, the gaseous medium sweepsendwise out of both the tubular members 52 and 56 to atmosphere.

Obviously, as soon as the tension. of the spring leaves the disc 44, itstendency to bind the counterbore of the ferrule 43 is reduced, and anytendency to form high pressure within the outer casing 40 will result inblowing oi the cap or disc 44 and relieving the pressure.

The fuse may be refilled by supplying a new terminal 5U and attachedsleeve 52 and filling 51 with the fusible element 48 and terminal 49.Preferably the spring 47 is shunted by a iiexible conductor.

In Fig. 12 I have shown an expulsion type of fuse embodying myinvention. In this case I employ a sleeve of insulation as shown at 57.

this sleeve being formed of bakellzed bcr, porcelain or glass. To thelower end of the sleeve 57 there is attached a ferrule 58 with aterminal screw 59 for clamping the lower end 60 of the exible fuseterminal 61 to theferrule 58. To the upper end of the sleeve 57 Iconnect an explosion chamber member 62. This is preferably formed of ametal casing cemented or otherwise secured upon the upper end of thesleeve 57 and having a threaded opening at its upper end in alignmentwith the bore of the tube 57 and normally closed by a threaded plug 63.To the threaded plug 63 on its lower end I connect a fuse terminal 64,and between the fuse terminal 64 and the fuse terminal 61 a fusible link65 is connected. On the outside of the lower end of the terminal 64 andthe upper end of the terminal 61 I mount a sleeve 66 of paperimpregnated with and filled with a mass of chlorinated naphthalene asindicated at 67.

Upon blowing of the active element 65 the arc which is formed isimmediately attacked by the arc extinguishing material in solid form,which, by the heat of the arc, is melted and vaporized to some extent.The pressure which results from the formation of the arc expels or inpart expels the paper sleeve 66 with its filling 67 of wax-like arcextinguishing material. If the explosion is particularly violent theentire sleeve with its mass of material and the terminal 61 may beexpelled through the sleeve 57.

The fuse may be refilled by removal of the threaded plug 63 andloosening of the terminal 59 to release the portion 60 of the flexibleterminal and an entirely new fuse and terminal attached to a plug suchas 63, dropped down through the open. end of the chamber 62, and downthrough the sleeve 57. The upper terminal 64 may be xedly secured to theplug 63 or releasably secured to the same, this feature being optionalIn all of the forms illustrated, the arc is brought into contact with amass of chlorinated naphthalene preferably in the solid form. Obviouslywithin my invention the liquid form may be ernployed, care being takento make the container sufficiently tight to retain the liquid form. Thecontact of the heat of the arc with the chlorinated naphthalenedissociates and the halogen element thereof attacks the metal vapor ofthe arc, forming non-conducting compounds which, being chilled andstabilized by the surrounding relatively cold mass, do not furtherdisintegrate under the electric arc, with the result that the fuseeffectually prevents sustained current flow.

To illustrate the fundamental action involved, I show in Fig. 13diagrammatically two metallic terminals 'l0 and '7l between which an arcis formed within the sleeve or housing '12 by current supplied through asuitable source as indictated at 73. An inlet nozzle 74 is directed intothe space in which the arc is formed and this is connected by a pipe 75through a control valve 76 with a tank of chlorine gas under highpressure, as indicated at 77. Assume that the arc is formed between theterminals l0 and '71 in a relatively confined space. I thereupon admitat high velocity and at relatively high pressure chlorine gas whichdisplaces the atmospheric air tending, by its chilling effect, to reducethe temperature within the container 72 and tending, by its chemicaleffect, to combine with the metal which is in extremely susceptible formto chemical action, whereby non-conducting compounds are formed fasterthan metal can be liberated from the terminals 70 and 71, with theresult that the arc is extinguished.

It will be seen that lt is desirable to employ as an active element amaterial which will have the ability to attack the active metal or otherconducting substance in the arc at a temperature less than thetemperature of the electric arc and with great rapidity.

Preferably such action should not add heat to the mass, but shouldrequire a temperature less than the temperature of the arc for its bestor optimum condition. The chlorinated naphthalene requires heat to breakit down to free the chlorine, and this, therefore, forms an idealcombination, since the reaction is endothermic to the extent ofrequiring the heat of the arc to liberate the chlorine, which chlorinein turn attacks the arc to form a compound which is non-conducting, orrelatively so, and which, due to the extraction of heat therefrom,becomes stabilized and will not again dissociate.

I do not intend to be limited to the details shown and described, nor tothe specific material which I have above described in detail, since I amconvinced by my experiments that fiuorine, as an active element, wouldbe even more effective for this purpose.

It may be that other negative elements or radicals combining with themetal of the fuse will be equally effective in forming a non-conductingcompound to extinguish the arc, and these, if discovered, I beg toinsert in this descrip tion hereafter as coming within the broad scopeof my invention.

Preferably the metals which I employ for the fusible link are such asaluminum, zinc, tin and lead. which are very quickly attacked by thehalogen group, but I do not wish to confine myself to these metals,since, at the heat of the electric arc, all of the ordinary baser metalscombine readily with the more active halogens.

I claim:-

l. In a fuse device, the combination of a container comprisingv an outersleeve of condensation product and an inner lining of fiber impregnatedin a solid waxy halogen derivative of naphthalene, and a fusible linkwithin said container.

2. In combination, an outer sleeve having a metallic cap at one end, ametallic ferrule at the other, said ferrule having a portion extendingbeyond the end of the sleeve, a removable closure for said end of theferrule, a spring secured to the cap within the sleeve, a pair ofterminals, one of which is connected to the spring, the other of whichis connected to the ferrule, a fusible link between said terminals and afilling of solid arc extinguishing material surrounding said fusiblelink, said material being converted from solid to liquid and from liquidto gas by absorption of the heat of the arc formed when said linkruptures to quench that arc.

3. In combination, an outer sleeve having a metallic cap at one end, ametallic ferrule at the other, said ferrule having a portion extendingbeyond the end of the sleeve, a removable closure for said end of theferrule, a spring secured to the cap within the sleeve, a pair ofterminals, one of which is connected to the spring, the other of whichis connected to the ferrule, a fusible I' link between said terminalsand a filling of solid arc extinguishing material surrounding saidfusible link, an inner sleeve for containing said solid mass of arcextinguishing material, said inner sleeve being connected to the springand movable thereby together with the movable terminal, and a thirdsleeve impregnated in said arc extinguishing material and interposedbetween said inner and outer sleeves to protect the latter from rupturewhen said link is ruptured.

4. In combination, an outer sleeve element, closure members for each endof the sleeve, a pair of terminal members electrically connected to eachof the closure members, one of said terminal members being movable', aspring connected to the movable terminal member for sep.- arating itfrom the other terminal` member, means for supporting a mass of solidarc extinguishing material around said terminals, a fusible elementimbedded within the mass of arc extinguishing material and connectingsaid terminals, and a mass of chlorinated naphthalene in said holdingmeans.

5. As an article of manufacture, a renewable fuse comprising a fusecartridge consisting of a fusible member encased in a lling ofchlorinated naphthalene and having terminal members projecting from saidcartridge, a mounting therefor consisting of a cup-like body conformingto the contour of said cartridge with terminal pieces projecting fromopposite ends of the body, to which pieces said cartridge terminalmembers are attached, and a casing surrounding said cartridge and body,from which casing said terminal pieces project.

6. In combination with a fuse cartridge having a fusible member whosemiddle portion is encased in a body of chlorinated naphthalene and whoseend portions form terminals projecting therefrom, a mounting comprisingknife blade terminal members spaced apart by a cradle in which saidcartridge rests, means for fastening said terminals to said knife blademembers,and means removably supported on said members for encasing saidcartridge and cradle.

'1. In combination with a fuse cartridge having a fusible member whosemiddle portion is encased in a body of chlorinated naphthalene and whoseend portions form terminals projecting therefrom, a mounting comprisingknife blade terminal members spaced apart by an insulating crade inwhich said cartridge rests, means for fastening said terminals to saidknife blade members, and means removably supported on said members forencasing said cartridge and cradle.

8. In combination with a fuse cartridge having a fusible member whosemiddle portion is encased in a cylindrical body of chlorinatednaphthalene and whose end portions form terminals projecting therefrom,a mo ting' comprising knife blade terminal members spaced apart by asemi-cylindrical insulating cradle in which said cartridge rests, means`for fastening said termi-1 nals to said knife blade members, and meansremovably supported on said members for encasing said cartridge andcradle.

9. As an article of manufacture, a. fuse comprising a casing havingremovable ends, contact strips extending from said ends, an insulatingcradle within said casing supported on the inner ends of said contactstrips, and a fuse cartridge supported in said cradle and havingterminals electrically connected to said contact strips.

10. In combination with a fusible metal encased in a body of chlorinatednaphthalene and projecting from the ends thereof, an open end insulatingtube into which said body fits, a metal expulsion chamber attached toone end of said tube, a plug attached to one of the projecting parts 0fsaid fuse and threaded into said chamber to close it, a metal ferruleattached to the outside of the other end of said tube, and means forattaching the other of said projecting ends of the fuse to said ferrulewithout closing the end of said tube to thereby permit the pressureformed by an arc in said naphthalene to expel said body from the tube.

1l. In an expulsion type fuse, an insulating tube, a metal expulsionchamber attached to one end of said tube, said chamber having a threadedopening opposite the end of said tube, a metal band or ferruleencircling the other end of said tube, a fuse cartridge comprising afusible strip encased in a body of chlorinated naphthalene, a threadedplug attached to one end of said strip, said plug being threaded intosaid opening to close the expulsion chamber when said cartridge is inplace, and a contact strip attached to said fusible strip and ferrule,said strip leaving the end of the tube open to permit expulsion of thenaphthalene body by the gases formed therein by the fusing of saidfusible strip.

l2. In an expulsion fuse, an outer tube with an expulsion chamberattached at one end thereof, a ring or ferrule encircling the other endof said tube, a fusible element attached to said ferrule and chamber, aninner tube loosely fitted in said outer tube and surrounding thatportion of the fusible element within said chamber, and a filler withinsaid inner tube and around said fusible member, said filler beingvolatilized by the arc formed by the fusing of said element to form anarc quenching gas, the pressure of which expels said inner tube fromsaid chamber through said outer tube to thereby separate the ends ofsaid fusible element to expedite the extinction of said arc by said gas.

13. In an expulsion fuse having an expulsion chamber closed at one endby a removable plug, an open ended tube extending from said chamber, afuse cartridge in said chamber, a connection between one end of saidfuse cartridge and said plug, a ferrule surrounding the open end of saidtube, a connection between the opposite end of said cartridge and saidferrule, and means within said cartridge acted upon by the arc caused bythe fusing of said fuse to form an arc quenching gas the pressure ofwhich expels said cartridge from said chamber through said tube.

14. In combination, a fuse casing comprising a sleeve of insulationhaving encircling .external terminals mounted upon the ends thereof, afuse within said casing adjacent one end thereof for connecting saidterminals, means connecting said fuse to said external terminals, saidmeans including a rod like terminal, and an elongated body of a solidcrystalline material surrounding one end of said fuse and said .rodliketerminal, said body lying within the bore of said one end of the sleeveand being adapted under the action of the arc formed upon blowing of thefuse to evolve a fluid having high arc extinguishing properties, saidrodlike terminal being free to move toward the other end of the sleevefor lengthening the arc and thereby to bring more of the arcextinguishing material within the influence of the are.

15. In combination, a fuse casing comprising a sleeve of insulationhaving encircling metallic members mounted upon its ends formingexternal electrical terminals, a fusible link within and adjacent oneend of said casing, a body of solid crystalline compound surroundingsaid link and extending a substantial distance beyond one end thereofand toward the other end of the casing, a rodlike metallic internalterminal extending through a portion of said body and being connected tothe adjacent end of the fuse, said internal terminal having electricalconnection with the external terminal at the other end of the casing andbeing movable upon blowing of the fuse toward said other end of thecasing to lengthen the arc and to extend its influence upon saidcompound, said compound being resolved by the heat of the arc formedupon blowing of the fuse to liberate a gaseous medium effective toextinguish the arc.

16. In combination, a fuse casing comprising a tube of insulatingmaterial, external terminals fixed on the tube. a pair of internalterminals connected to the external terminals, a fusible link betweenthe internal terminals, one of said internal terminals being movableaway from the other internal terminal upon melting of the fuse link,means for automatically separating said terminals upon melting of thefusible link, and a self-sustaining body of solid arc extinguishingmaterial having a bore within which the arc is drawn by separation ofsaid internal terminals, said arc extinguishing material being heated bythe arc to liberate an arc extinguishing fluid in said bore.

17. In combination, a. fuse casing comprising a sleeve of insulationhaving metallic members upon the-ends thereof forming external circuitterminals, a fusible link within said casing, a self-sustaining body ofa solid arc extinguishing material substantially lling the bore of apart of the casing and surrounding the fuse, said solid arcextinguishing material being affected by the heat of the arc to liberatean arc extinguishing medium of great effectiveness, a metallic fuseterminal extending through a part of said body of arc extinguishingmaterial and being connected to an adjacent end of the fuse, theremainder of the bore oi the tube being free to permit retraction ofsaid fuse terminal upon blowing of the fuse, and a spring for retractingsaid terminal to lengthen the arc and bring a greater part of said bodyof arc extinguishing material within the influence of said arc.

18. In combination, a fuse casing comprising a sleeve of insulationhaving metallic members upon the ends thereof forming external circuitterminals, a fusible link within said casing, a self-sustaining body ofsolid arc extinguishing material substantially filling the bore of apart of the casing and surrounding the fuse, said solid arcextinguishing material being affected by the heat f the arc to liberatean arc extinguishing fluid of great effectiveness, a metallic fuseterminal extending through part of said body of material and beingconnected to an adjacent end of the fuse. the remainder of the bore ofthe tube being free to permit retraction of said fuse terminal uponblowing of the fuse, and a. spring for moving said terminal to lengthenthe arc within said body of material. said terminal being drawn throughthe body of material whereby the arc acts upon a greater part of thebody of material and is subjected to greater arc extinguishing action atthe same time that its length is increased.

19. In combination, a pair of terminals, a fuse connected between saidterminals, a self-sustaining body of solid arc extinguishing materialdisposed adjacent the fuse and adapted when subjected to the arc toevolve an arc extinguishing medium, and means for separating saidterminals upon blowing of the fuse.

. s wei 20. In combination, a fuse casing, ay fuse in the casing. asurrounding tubular body of self-sustaining solid arc extinguishingmaterial defining a fuse chamber, said material being adapted, under theinfluence of the arc, to evolve a gaseous are extinguishing medium, andan adjacent chamber communicating with the fuse chamber and into whichgaseous medium evolved from the body of material is adapted to beprojected, whereby the motion of the gaseous medium relative to the arcis benecial in extinguishing the arc.

21. In combination, a pair of fuse terminals, a fuse between them, aspring free to separate said terminals to extend the length of an arcformed upon blowing of the fuse, and an elongated self-sustaining hollowbody surrounding the fuse and within the bore of which the arc isadapted to be lengthened, for evolving from the inner walls thereof bythe heat of the arc a gaseous arc extinguishing medium, said hollow bodyconfining and directing the ow of the gaseous medium into the arc andlongitudinally of the bore of the body.

22. In combination, a pair of terminals, a fuse 1 connected between saidterminals. a body of selfsustaining crystalline compound disposedadiacent the fuse and adapted when subjected to the heat of the arc toevolve an arc extinguishing medium means cooperating with said body todirect the arc extinguishing medium into the arc, and a spring forseparating said terminals upon blowing of said fuse.

23. In combination, a pair of terminals between which an arc is adaptedto be formed, a surround- 1 ing casing substantially embracing the arcsaid casing comprising, a crystalline self-sustaining solid which byaction of the arc liberates fluids which have high arc extinguishingproperties and constituting means to inject these fluids at high uvelocity laterally into the arc. and means for separating the terminals.

24. In a fuse, a tubular self-sustaining solid having a bore, the wallsof which comprise a self-sustaining surface of an arc extinguishingcompound from which, by the action of an are, a gaseous arcextinguishing medium is evolved, fuse terminals and a fuse between saidterminals, said fuse upon being blown forming an arc within said tubularbore, said gaseous medium filling the said 1 u bore and being driven outof one end thereof to extinguish the arc.

25. In a protective device of the class described, a tubular housingcomprising ferrules constituting external terminals, a pair of internaltermi- 13g nais, a spring connected to one of the internal terminals forseparating the same, a. fuse connected between said internal terminals,and means for supplying a gaseous arc extinguishing medium to extinguishthe arc upon blowing of the fuse, 35

said means including a tubular member providing a self-sustainingsurface of solid arc extinguish ing material adapted to be acted upon bythe arc to release gaseous are extinguishing material and to extinguishthe arc upon moderate overload, and a second tubular member of largerbore than the first tubular member adapted, in the case of heavyoverload, to be acted upon by the arc and to evolve gaseous arcextinguishing material for extinguishing the arc therein. 26. The methodof interrupting current flow through a fuse, which comprises blowing thefuse to vaporize the metal of the same, establishing an arc through saidmetallic vapor, laterally confining the arc, injecting a gaseous mediumof relatively low arc sustaining character into the laterally connedspace occupied by said arc so long as the arc persists and therebydrivingout the metallic vapor and supplanting it with said gaseousmedium.

27. The method of extinguishing an arc, which comprises laterallyconfining the arc, evolving a gaseous arc extinguishing medium bytheaction of the heat of the arc, said gaseous medium sweeping out of saidlaterally confined space metallic vapors released by the arc andsupplanting them by said gaseous medium so long as the arc continues.

28. The method of extinguishing an arc, which comprises laterallyconfining the arc in the presence of a deionizing agent to causeevolution of gaseous medium the pressure of which rises and creating arapid iiow of said gaseous medium substantially longitudinally of thearc to drive out metal vapors and break up and deionize the arc.

29. In a device of the class described, lthe combination of a fusehousing having metallic Yferrules of a tubular explosion chamber withinsaid housing, a fusible link within said housing, there being an arcextinguishing material subject to the action of the arc caused byblowing of the fuse for forming within the explosion chamber a gaseousarc extinguishing medium which sweeps out of the explosion chamber themetallic vapors of the fused link and supplants it with a medium oflower arc sustaining character.

30. In a device of the class described, the combination of a fusehousing having metallic ferrules of a tubular explosion chamber withinsaid housing, a fusible link within said housing, there being an arcextinguishing material subject to the action of the arc caused byblowing of the fuse for forming within the explosion chamber a gaseousarc extinguishing medium which sweeps out of the explosion chamber themetallic vapors of the fused link and supplants it with a medium oflower arc sustaining character, and means for automatically extendingthe length of the arc upon melting of said link.

31. The method of interrupting current flow through an arc, whichcomprises continuously evolving by the heat of the arc an arcextinguishing medium so long as the arc persists, directing said mediuminto the arc, confining a portion of said medium in contact with the arcagainst movement laterally of the are while permitting movement of themedium longitudinally of the arc to displace the conducting gases of thearc longitudinally.

32. The method of interrupting current ow `through a fuse, whichcomprises blowing the fuse to vaporize the metal of the same,establishing an arc through said metallic vapor. subjecting to the heatof the arc a material capable of evolving an arc extinguishing medium,continuously evolving said medium so long as the arc persists, andcreating a continuous blast of said medium longitudinally of the arc solong as the arc persists, to displace the conductive vapor of the arclongitudinally of the arc.

33. The method of interrupting' current iiow through a fuse, whichcomprises maintaining alongside the fuse a material capable of evolvinga gaseous arc extinguishing medium when subjected to the heat of an arc,blowing the fuse to vaporize the metal oi' the same, establishing an arcthrough said metallic vapor, evolving continuously from said material bythe heat of the arc a gaseous arc extinguishing medium,

and coniining said gaseous medium against lateral ow away from the arcwhile permitting flow of said medium longitudinally o! the arc.

34. The method o1' interrupting current flow through a fuse, whichcomprises maintaining alongside the fuse a material capable of evolvinga gaseous arc extinguishing medium when subjected to the heat of an arc,blowing the fuse to vaporize the metal of the same, establishing an arcthrough said metallic vapor, evolving from said material by the heat ofthe arc a gaseous are extinguishing medium, conning said gaseous mediumagainst lateral flow away from the arc while permitting flow of saidmedium longitudinally of the arc, and separating the terminals of thearc to extend the length of the arc to subject more of the aforesaidmaterial to the heat of the arc and thereby accelex-ating the evolutionof said medium and the longitudinal low thereof.

35. The method of interrupting current flow through a fuse, whichcomprises blowing the fuse by current flow therethrough, establishing anarc through the metal vapor, confining the lateral expansion of saidmetal vapor and permitting longitudinal expansion of the same,continuously absorbing the heat of the arc so long as the arc persistsby an arc extinguishing material, continuously evolving from saidmaterial by said absorbed heat a gaseous are extinguishing medium, anddirecting the gaseous arc extinguishing medium longitudinally of the arcto displace said metallic vapors of the arc.

36. In combination, a fuse housing, a pair of terminals disposedtherein, a' fuse connected between said terminals, arc extinguishingmaterial disposed within the housing being directly exposed to the arcformed upon blowing of the fuse, said material, upon blowing of the fuseand formation of an arc between the terminals, being converted into agaseous arc extinguishing medium and being discharged into the arc, andtubular means within said housing, said means surrounding a part of thearc and producing a condition of higher pressure of said medium at onepoint on the length of the arc than at another, whereby now of thegaseous arc extinguishing medium through said tubular meanslongitudinally of the arc is created and maintained so long as the arcpersists.

37. In combination, a housing, a pair of terminals therein, a fusebetween the terminals, a spring for moving one of the terminals awayfrom the other when the fuse is blown, a tubular body in the housing,said body having a. bore embracing a part of the arc, and a mass of areextinguishing material, said body presenting said arc extinguishingmaterial to the heat of the arc to cause said material to release an arcextinguishing medium which is directed into the arc within the bore toexpel the conducting gases of the arc longitudinally out of said bore.

38. In a protective device of the class described, a tubular housingcomprising ferrules constituting external terminals, a pair of internalterminais connected to said external terminals, a spring connected toone of the internal terminals for separating the one internal terminalfrom the other, a fuse connected between said internal terminals, arcextinguishing material within the housing, said material being subjectedto the heat of the arc upon blowing of the fuse to evolve a gaseous arcextinguishing medium. and means within the tubular housing providing arst bore of reduced diameter within which the arc is formed and a secondbore of larger diameter than the first bore into which latter bore thearc is extended by movement of the movable internal terminal, the arcacting upon said arc extinguishing material in both said bores fr theevolution of said gaseous arc extinguishing medium so long as the arcpersists.

39. In a fuse device, a sleeve of insulation, a pair of externalterminals upon the ends of said sleeve, one of said terminals closingthe end of the sleeve, a conductor extending longitudinally through saidsleeve of insulation and connecting said terminals, said conductorcomprising a fusible link at its intermediate portion, a second sleevewithin said iirst sleeve surrounding said fusible link, and a mass ofsolid crystalline arc extinguishing material supported inside saidsecond sleeve, said material absorbing heat from the arc formed uponblowing of thefuse and evolving a gaseous arc extinguishing medium whichis confined against lateral expansion by said second sleeve, said secondsleeve being adapted to be expelled from the end of the first sleeve byaction of said gaseous medium.

40. In a fuse, a fusible link, a. movable terminal for the link, amovable arcing chamber for the link, 'said chamber being provided withan arc extinguishing material adapted to act upon the arc therein, andmeans acting upon fusing of the link to retract the movable terminal andthe chamber.

41. In a fuse, a fusible link, a pair of terminals for said link, and amovable arcing chamber for the link, said chamber being provided with anarc extinguishing material adapted to act upon the arc therein, saidterminals being adapted to be separated upon the blowing of the link andsaid chamber being attached to one of said terminals.

42. In a. fuse, a fusible link, a supporting terminal for one end of thelink, a movable arcing chamber for the link, said chamber comprising` aninsulating sleeve, an arc extinguishing material adapted to act upon thearc within the chamber when the link fuses, a movable terminal for thelink extending into and anchored to the chamber, and a spring forretracting the latter terminal and the chamber when the link fuses.

43. In a fuse, a fusible link having separable terminals, a spring forseparating the terminals, and an insulating arcing chamber in which thearc is drawn, said chamber containing a charge of arc extinguishingmaterial from which a gaseous arc extinguishing medium is driven ofl' bythe heat of the arc, the spring being external to the chamber. Y

44. Ina fuse, the combination of a main housing comprising a tubularsleeve of insulation bearing upon its ends external terminals in theform of metal sleeves, one of said metal sleeves having an open bore,the other of said metal sleeves being provided with a spring anchorage,an arcing chamber within the main housing comprising a sleeve ofinsulating material, said latter sleeve containing a` solid arcextinguishing material from which a gaseous arc extinguishing medium isevolved by the heat of the arc drawn upon melting of the fusible link, aconnecting member having a cylindrical contacting portion F.lttingwithin the open bore of said one metal terminal sleeve, a terminal roddisposed within the arcing chamber and with one end extending toward theconnecting member and the other end extending outside said last namedchamber,

a fusible link connecting said one end of the terminal rod with theaforesaid connecting membe r, and a spring within the main housingconnested at one end of said extending end of the terminal rod and atits other end to said spring anchorage.

45. In a fuse, the combination of a sleeve of insulation, a metalconnecting member having a cylindrical contact portion disposed at oneend of the sleeve, said sleeve containing a. charge of arc extinguishingmaterial from which there is evolved a gaseous arc extinguishing mediumby the heat of the arc occurring upon the blowing of the fusible link, arod like terminal lying within the bore of the sleeve and beingsurrounded by said arc extinguishing material, said terminal projectingfrom the end of the sleeve opposite the metal connecting member, and afusible link connected between the metal connecting member and theadjacent end of the rodlike terminal.

46. In a fuse, the combination of a sleeve uf insulation, a metalconnecting member having a cylindrical contact portion disposed at oneend of the sleeve, said sleeve containing a charge of said arcextinguishing material from which there is evolved a gaseous arcextinguishing medium by the heat of the arc occurring upon the blowingof the fusible link, a rodlike terminal lying within the bore of thesleeve and being surrounded by said are extinguishing material, saidterminal projecting from the end oi' the sleeve opposite the metalconnecting member. a transverse pin extending through the rodliketerminal and having its ends anchored in the adjacent end of the sleeve,a fusible link within the sleeve connected between the metal connectingmember and the adjacent end of the rodlike terminal.

47. In a fuse, the combination of a sleeve of insulation, a metalconnecting member having a cylindrical contact portion disposed at oneend of the sleeve, said sleeve containing a charge of arc extinguishingmaterial from which there is evolved a gaseous arc extinguishingmaterial by the heat of the arc occurring upon the blowing of thefusible link, a rodlike terminal lying within the bore of the sleeve andbeing surrounded by said arc extinguishing material, said terminalprojecting from the end of the sleeve opposite the metal connectingmember, and a fusible link connected between the metal connecting memberand the adjacent end of the rodlike terminal, said metal connectingmember being adapted to make telescopic connection with an electricalterminal and said rodlike terminal having its outwardly projecting endformed to provide a coupling for a tension spring.

48. A refill for a fuse, comprising a tubular body of insulation, acylindrical connecting member mounted at one end of the body, a chargeof are extinguishing material within the tubular body, a terminal roddisposed partly within the tubular body and having one end extendingoutside said tubular body and formed to provide part of an attachableand detachable coupling, and a fusible link connecting the opposite endof the terminal rod to the connecting member, said link being disposedwithin the tubular body.

49. In a fuse, in combination with a main housing comprising a sleeve ofinsulation having external metallic terminals mounted on the ends of thesleeve, one of said external terminals being open and having linkcoupling means, and the other external terminal having anchorage for abreech block to close the same, a removable breech block cooperatingwith said anchorage, a 150 link comprising a fusible portion disposedadjacent the breech block and comprising a flexible portion attached tosaid link coupling means, and an inner sleeve carried by the link andsurrounding the fusible portion of the link, said inner sleevecontaining a charge of arc extinguishing material in position to beacted upon by the arc occurring upon blowing of the fusible portion.

50. In a fuse, in combination with a main housing comprising a sleeve ofinsulation having external metallic terminals mounted on the ends of thesleeve, one of said external terminals being open and having linkcoupling means, the other external terminal having anchorage for abreech block to close the same, a removable breech block cooperatingwith said anchorage, a link comprising a fusible portion disposedadjacent the breech block and comprising a flexible portion attached tosaid link coupling means. and an inner sleeve carried by the link andsurrounding the fusible portion of the link, said inner sleevecontaining a charge of arc extinguishing material in position to beacted upon by the arc occurring upon blowing of the fusible portion,said inner sleeve extending partly within the lrst sleeve of insulationand loosely fitting the same, said inner sleeve being adapted to beexpelled upon operation of the fuse.

51. In a fuse, in combination with a main housing, comprising armainsleeve of insulation having external terminals in the form of metallicferrules mounted on the ends of the sleeve, one of said ferrulesextending beyond the end of the sleeve to form an explosion chamber, aremovable closure for said one ferrule, a removable inner sleeve ofinsulation within said explosion chamber, said inner sleeve containing acharge of arc extinguishing material which under the action of an arcreleases a gaseous arc extinguishing medium, and an expulsion linkextending through said sleeves and connecting said ferrules, said linkcomprising a fusible portion disposed within said inner sleeve.

52. A rell for an expulsion fuse, comprising a breech block havingdetachable coupling means, a link comprising a fusible portion adjacentthe breech block, a sleeve surrounding the fusible portion, and a chargeof arc extinguishing material within the sleeve adjacent the fusibleportion.

53. A refill for a fuse. comprising an enlarged upper terminal member, alink connected thereto, said link comprising a fusible portion adjacentsaid terminal member, and a sleeve of insulation about said fusibleportion, said sleeve containing a charge of arc extinguishing materialadapted to be vaporzed by the heat of the arc. l

54. In an expulsion fuse, a main sleeve having ferrules, oneferrulebeing open and being provided with a binding post for a fuselink, the other ferrule being provided with a breech block closure, alink connecting said ferrules and being held by said binding post andclosure, said link having a fusible portion adjacent the closure, and acharge of arc extinguishing material surrounding the fusible portion ofthe link, said link and charge of arc extinguishing material beingreplaceable after operation ofthe fuse by removal of the closure.

55. In a fuse, a main fuse housing, comprising an outer sleeve ofinsulation with metal ferrules forming external terminals upon the endsthereof, the upper ferrule having an internal circular seat providing acontact. a plate-like contact member having a peripheral flange engagingthe circular seat, a fuse terminal secured to the central part of saidcontact member, a movable fuse terminal within the housing, a springconnecting said movable fuse terminal with the lower ferrule, a fusiblelink connecting said fuse terminals, an explosion chamber comprising asleeve of -insulating material surrounding the link and being carried bythe movable terminal and movable therewith, and a charge of arcextinguishing material which acts upon the arc within the explosionchamber when the fusible link blows.

56. In a fuse, a tubular housing of insulation having a metal ferrule ateach end, a fusible link within the housing, a spring connected to oneend of the link and to the first ferrule and placing the link undertension, and an arched terminal piece connected at its central archedportion to the other end of the link whereby it sustains the tension ofthe fuse, said arched terminal piece being supported at points remotefrom its central portion within the second ferrule and being expandedlaterally into engagement with the inside walls of the ferrule toprovide electrical contact with said second ferrule.

57. In combination, a fuse housing, comprising an outer sleeve ofvitreous insulation and comprising contact ferrules engaging the ends ofsaid sleeve, the upper ferrule having an open bore into which a fuse andterminalmay be introduced. a terminal removably mounted in said bore, afuse link connected to said terminal, a spring connected to the lowerend of the link, said spring upon blowing of the fuse being adapted toextend the length of the arc within the housing, and a sleeve of fibrousinsulation within the vitreous sleeve protectingthe vitreous sleeve frominjury by the arc.

58. A fuse comprising a link having a localized fusible portion, arcextinguishing material disposed adjacent the localized fusible portionand adapted upon the blowing of said localized fusible portion and theformation of an arc thereat to evolve a gaseous arc extinguishing mediumso long as the arc persists and an open ended insulating sleevesurrounding the link and conning the arc extinguishing material and theresultant gaseous arc extinguishing medium to direct the flow of saidmedium endwise out of said sleeve.

59. A fuse comprising in combination an insulating sleeve, a metalliccircuit extending through the sleeve, and having a fusible sectionadjacent one end of the sleeve. a cylindrical body surrounding thefusible section and containing an arc extinguishing material which underthe heat of the arc. formed upon blowing of the fusible section evolvesa gaseous arc extinguishing medium, said body being adapted upon blowingof 'said fusible section to be moved toward the opposite end of thesleeve, replacing a portion of the metallic circuit with a column of thegaseous arc extinguishing medium to extinguish the arc and to preventreestablishment of the same.

60. In a fuse, a tubular housing having at the rst end an open metalferrule and at the second end a closed metal ferrule, a fusible link inproximity to the rst end of the housing, a spring connected to one endof the fusible link for applying tension to the link, a releasableterminal mounted within the open ferrule and forming a conductiveconnection between the adjacent end of the fusible link and said rstnamed ferrule, said spring tensioning the link and forcing thereleasable terminal into contact laterally with the inner walls of thefirst named ferrule.

61. In a fuse, a tubular housing having at the first end an open metalferrule and at the second end a closed metal ferrule, a fusible link inproximlty to the first end of the housing, a spring connected to one endof the fusible link for applying tension to the link, a releasableclosure fltting into the open ferrule and forming a conductiveconnection between the adjacent end of the fusible link and said firstnamed ferrule, said spring tensioning the link and forcing thereleasable closure into contact laterally with the inner walls of theiirst named ferrule, and arc extinguishing material disposed within thehousing and adapted to be acted upon by the arc to form an areextinguishing medium.

62. In a device of the class described, a selfsupporting tubular sleevecomprising an arc extinguishing material which is adapted under theaction of an arc to evolve a gaseous arc extinguishing medium the sleevehaving a. bore open at one end, and serving to direct the flow of saidgaseous medium endwise through the bore.

63, Ina device of the class described, a selfsupporting open endedtubular sleeve the bore of which is coated with an arc extinguishingmaterial which is adapted under the action of an arc to give oi agaseous arc extinguishing medium.

64. In a device of the class described, a selfsupporting tubular sleeveimpregnated with an arc extinguishing material which is adapted underthe action of an arc to give off a gaseous arc extinguishing medium.

65. In a fuse, a pair of fuse terminals, a fuse connecting saidterminals, an arc extinguishing chamber in which the arc formed onblowing of the fuse is extended, and arc extinguishing material withinthe chamber, said chamber being elongated as the arc is extended.

66. In a fuse, a pair of fuse terminals, a fuse between the terminals,an arc extinguishing chamber within which the arc formed on blowing ofthe fuse is drawn, and spring means for elongating the chamber and thearc within the chamber.

6'7. In combination, an elongated tubular housing having contactferrules at the ends thereof, the upper ferrule having an open bore intowhich a fuse and terminal may be introduced, a terminal removablymounted in said bore, a fuse link connected to said terminal, a springconnected to the lower end oi' the link, said spring upon melting of thelink being adapted to extend the length of the arc within the housing,said housing comprising a transparent portion to permit visualinspection of the spring whereby the operator may know whether the linkhas yielded, said housing comprising also a separate sleeve of fibrousinsulation surrounding the link and adapted to withstand the arc whichis drawn upon melting of the link, said sleeve of ibrous insulationextending from the upper terminal substantially as far down as thehousing is exposed to the arc when the arc is extended by the spring.

68. In a fuse, a fusible link and a surrounding sleeve comprising anabsorbent insulating material wet with a liquid arc extinguishingmaterial which material is adapted, under the inuence of the arc, toevolve a gaseous arc extinguishing medium, said sleeve having a borethrough which said arc extinguishing medium is guided in its now.

69. In a fuse, a fusible link, a surrounding tube of insulation and alongitudinally extending member within said tube lying alongside thelink, said member being self-sustaining and having incorporated withinits body an arc extinguishing material which material is driven off fromwithin the body of the member by the heat of the arc.

'70. In a device of the class described, a fusible link, a sleeveembodying an arc ex material surrounding the link, said sleeve beingporous to permit the evolution of the are extinguishing material fromthe body of the sleeve under the heat of the arc.

7l. In a fuse, a fusible link having separable terminals, a spring forseparating the terminals, and an insulating arcing chamber surroundingthe link, said chamber containing a charge of arc extinguishing materialfrom which a gaseous arc extinguishing medium is driven off by the heatof the arc, the spring being external to the chamber, said chamberhaving a vent at the end thereof opposite the spring.

72. A refill for a fuse comprising an upper terminal member, a fusiblelink connected thereto. a lower terminal member connected to the link, asleeve of insulating material about said link, said sleeve containing acharge of are extingulshing material adapted to be vaporized by the heatof the arc. and a closure member for one end of the sleeve, the lowerterminal member extending out of the sleeve and having coupling meansfor the attachment of a spring.

73. A refill for a fuse comprising an upper terminal member, a' linkconnected thereto, said link comprising a fusible portion adjacent saidterminal member, and a sleeve of insulation about said fusible portion,said sleeve containing a charge of arc extinguishing material adapted tobe vaporized by the heat of the arc, the lower terminal member extendingout of the sleeve and having coupling means for the attachment of aspring, said upper terminal member constituting a closure for the upperend of the sleeve.

74. In combination, a tubular fuse housing comprising a sleeve ofinsulation having metallic ferrules at its ends, said ferrules formingexternal circuit terminals, a tubular fuse charnber disposed Within saidhousing adjacent an end thereof, a rodlike fuse terminal projecting intoone end oi' said chamber, said rodlike tern'iinal being electricallyconnected to one of said ferrules, a flexible conductor forming saidelectrical connection, a removable disklike closure for the other end ofthe chamber, a fuse terminal in the other end of the chamber and beingelectrically connected to the other of said ferrules, a fusible link inthe chamber connecting said fuse terminals, and a charge of arcextinguishing material disposed within said chamber.

75. In combination, a tubular fuse housing comprising a sleeve ofinsulation having metallic ferrules at its ends, said ferrules formingexternal circuit terminals, a tubular fuse chamber disposed within saidhousing adjacent an end thereof, a rodlike fuse terminal projecting intoone end of said chamber, said rodlike terminal being electricallyconnected to one of said ferrules, a removable disklike closure for theother end of the chamber, a fuse terminal in the other end of thechamber and being electrically connected to the other of said ferrules,a fusible link in the chamber connecting said fuse terminals, a chargeof arc extinguishing material disposed Within said chamber, and a springin the housing for retracting said rodlike terminal upon melting of thefusible link.

CERTIFICATE 0F CORRECTION.

Reissue No. 19,097.

CLARENCE RINGWALD.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows: Page 8,line 100, claim 4 6, for the word "said" read solid; and that the saidLetters Patent should be read with this correction therein that the samemay conform to the record of the case in the Patent Office.

Signed and sealed this 3rd day of April, A. D. 1934.

F. M. Hopkins' (Seal) Acting Commissioner of Patents.

February 27, 1934.

